Commit abb0eb0b authored by Qingfang Deng's avatar Qingfang Deng Committed by Jakub Kicinski
Browse files

ppp: simplify input error handling 



Currently, ppp_input_error() indicates an error by allocating a 0-length
skb and calling ppp_do_recv(). It takes an error code argument, which is
stored in skb->cb, but not used by ppp_receive_frame().

Simplify the error handling by removing the unused parameter and the
unnecessary skb allocation. Instead, call ppp_receive_error() directly
from ppp_input_error() under the recv lock, and the length check in
ppp_receive_frame() can be removed.

Signed-off-by: default avatarQingfang Deng <dqfext@gmail.com>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 58e4d35a

drivers/net/ppp/ppp_async.c

+1 −1
Original line number Diff line number Diff line
@@ -491,7 +491,7 @@ static void ppp_async_process(struct tasklet_struct *t) 
	/* process received packets */

	while ((skb = skb_dequeue(&ap->rqueue)) != NULL) {

		if (skb->cb[0])

			ppp_input_error(&ap->chan, 0);

			ppp_input_error(&ap->chan);

		ppp_input(&ap->chan, skb);

	}

drivers/net/ppp/ppp_generic.c

+10 −21
Original line number Diff line number Diff line
@@ -2383,12 +2383,10 @@ ppp_input(struct ppp_channel *chan, struct sk_buff *skb) 
	rcu_read_unlock_bh();

}



/* Put a 0-length skb in the receive queue as an error indication */

void

ppp_input_error(struct ppp_channel *chan, int code)

ppp_input_error(struct ppp_channel *chan)

{

	struct channel *pch = chan->ppp;

	struct sk_buff *skb;

	struct ppp *ppp;



	if (!pch)
@@ -2397,12 +2395,9 @@ ppp_input_error(struct ppp_channel *chan, int code) 
	rcu_read_lock_bh();

	ppp = rcu_dereference_bh(pch->ppp);

	if (ppp) {

		skb = alloc_skb(0, GFP_ATOMIC);

		if (skb) {

			skb->len = 0;		/* probably unnecessary */

			skb->cb[0] = code;

			ppp_do_recv(ppp, skb, pch);

		}

		ppp_recv_lock(ppp);

		ppp_receive_error(ppp);

		ppp_recv_unlock(ppp);

	}

	rcu_read_unlock_bh();

}
@@ -2414,8 +2409,6 @@ ppp_input_error(struct ppp_channel *chan, int code) 
static void

ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch)

{

	/* note: a 0-length skb is used as an error indication */

	if (skb->len > 0) {

	skb_checksum_complete_unset(skb);

#ifdef CONFIG_PPP_MULTILINK

	/* XXX do channel-level decompression here */
@@ -2424,10 +2417,6 @@ ppp_receive_frame(struct ppp *ppp, struct sk_buff *skb, struct channel *pch) 
	else

#endif /* CONFIG_PPP_MULTILINK */

		ppp_receive_nonmp_frame(ppp, skb);

	} else {

		kfree_skb(skb);

		ppp_receive_error(ppp);

	}

}



static void

drivers/net/ppp/ppp_synctty.c

+1 −1
Original line number Diff line number Diff line
@@ -483,7 +483,7 @@ static void ppp_sync_process(struct tasklet_struct *t) 
	while ((skb = skb_dequeue(&ap->rqueue)) != NULL) {

		if (skb->len == 0) {

			/* zero length buffers indicate error */

			ppp_input_error(&ap->chan, 0);

			ppp_input_error(&ap->chan);

			kfree_skb(skb);

		}

		else

include/linux/ppp_channel.h

+1 −1
Original line number Diff line number Diff line
@@ -55,7 +55,7 @@ extern void ppp_input(struct ppp_channel *, struct sk_buff *); 


/* Called by the channel when an input error occurs, indicating

   that we may have missed a packet. */

extern void ppp_input_error(struct ppp_channel *, int code);

extern void ppp_input_error(struct ppp_channel *);



/* Attach a channel to a given PPP unit in specified net. */

extern int ppp_register_net_channel(struct net *, struct ppp_channel *);

net/atm/pppoatm.c

+1 −1
Original line number Diff line number Diff line
@@ -228,7 +228,7 @@ static void pppoatm_push(struct atm_vcc *atmvcc, struct sk_buff *skb) 


error:

	kfree_skb(skb);

	ppp_input_error(&pvcc->chan, 0);

	ppp_input_error(&pvcc->chan);

}



static int pppoatm_may_send(struct pppoatm_vcc *pvcc, int size)